<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        var paw = prompt("请输入你的密码");
        if ( (/^[a-zA-Z]\w{5,15}$/).test(paw)) {
            alert("密码正确")
        } else {
            alert("密码应该包含数字，小写字母和大写字母")
        }
    </script>
</head>
<body>

</body>
</html>